SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c063aedaebac7bb3e83bd248d2da429c64024a4bd4884cc03bd84c173c18d5b3' 
  AND token = 'T1FpAlHaiyzJIP4nAspuBfG/LuJU+j1iA6iP2vGk5S4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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