SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '603e82bde4a5b32d7ab2005863684f17608c01819e4aa1d94d820a8f24a92201' 
  AND token = 'QN/iX3aXFtk1yVgsrplWePGmDE0XmX8rv0Mg2fv9XOU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

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