SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ffbcb6b64e7513558df89c19ceb6188a1a666d09f9da69d073666defbfb2f55a' 
  AND token = '/IsUrdi6Pf1EC9xQkoLmOpIVNnQmJ2EntxobdtmAGmg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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