SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a59465354d7fc7b11e36222590fc6442924a2100627a776b31d12f3d21d61886' 
  AND token = 'D5DYN94tpswkpCYaT/zgeSs+fL4S4ZIbU8cCUVf7Vi8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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