SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1c1e682b716079527e165794d577d37362855f1190d134d749179a2dbe29e69' 
  AND token = 'spsPIR6yasIlQlyIAvtwtaFVQqpRRN6Vsc1Z1l6nbA0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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