SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f86c113146314f9125252c5054e04f70d448df521dcd27f1ede0a7329e398d45' 
  AND token = 'GmsmijjaKb5bWvGL0KSuyzFA6Qgjx2LD/OSJCx+isrU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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