SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cdee1f546dc2ac465a63c8d86527f8786f048414974f0efefa56441811ffab9' 
  AND token = '0pICDcjfSF2DsJd3iFF8wNQOX4/+XCVKb6KYF2x3Ze8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

JSON explain

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