SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bb56530b1465e453bde1071ac99cd7b36d545f14aca49059793e46bf9d709ad' 
  AND token = '5ukYBagwQ9DdiLli3r63M2RpwpC/DJ9JPbS7B7U3Lv4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00079

JSON explain

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