SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'fe0552b97dabf69bdc1eabec2896ef339da9ae980b948e49a256d85a194ed301' 
  AND token = 'kgzi8Pg1xI+XOCkzgqYanGvHA/f6MmYl/DqfcrhrNwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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