SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b6e3a4be0e3541435cf0ca18c1b72124edceaaf69af01794a88fe7d20d94b7cf' 
  AND token = 'ICjM6td+viAFpH4vEEarD/uoDjDtH5cJkcrDPzrC8yQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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