SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8455259711187c0097ba7a84d902c1bd98b66317d5c03ff4053ca38a1ebf7036' 
  AND token = 'ZgVY+G4H2xma/6tcGrZhY7hGYtG6K8tN6zXM4rgTUbE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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