SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2f979a5a16f1e3c14e4ab3687013a394551f6511d70241fcd9829a49be63448c' 
  AND token = 'vf8i3wxLLilka1ajqTlqh4TtyN3IEJ3/beCPBw50XrY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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