SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e987e9c651f72dd0413f6a7b251cc72699cb99cc65f4e7e16bbab656cba4f16a' 
  AND token = 'Qzjd3nnZGGLVt4f2iAEaFHUhZ4qebwkLRR1VQIPYYe8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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