SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ab3bd8a7c07a7fe6a975f942efffda759dd8840964f01dc9707d65332103344' 
  AND token = 'PDeOMhOGA9SjbcumZZRYsC/FV6rrKnNIQ8GHGqmDWYA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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