SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da0b51c24ae2c70ae2840cf8dbfc741062f84d325d591dc58b10fb9c61abe95e' 
  AND token = 'RL0gK4+wItVIsqBcougrZ2GM/inpFyGWT8lyZdLdcCk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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