SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1035b22270fa26d197b3e0e28abff45602412ed2905c98899e1d3546f809c3af' 
  AND token = '9DG1nqn36Gch9wFw9s4UbNHGBksY0vDjz4w2/LB++qw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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