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SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4d35d1d9fa8d1258ffa48cc6b73456cbbcb350a3e303dd1d2c54542e216b54af' 
  AND token = 'ra3yxt0EOQWuIV5aRt5TC4PuhlrqohKWZd+P4JFS5+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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