SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '992da90093c8d34314a120e70c5de0276e57eb17ec440b27f7d5c798d6f3b308' 
  AND token = 'TZisLRSQeSwgi4PFXnSTHBeGmIvYAlSB0nARR+PwRtQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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