SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0f9178ac1105a4a026251b1717e75d6742becff0d1af78b5ef713bb68dadf20' 
  AND token = 'sLSPGmYH02FBtTPkACGuHEyYTUFp+nQ9TfNv9tO9bTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}