SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a2a753073ae82828b3be2baceb614e14120e084f17d052749cd3f8ce44252c9' 
  AND token = 'b689I4xn44xNujPrvoDqsqhtOOm0Pl9gNrtHDvmQpMs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}